1. Field of the Invention
The present invention relates to an apparatus for detecting particles in flat glass and a detecting method using the same, and more specifically, to an apparatus for detecting particles in flat glass and a detecting method using the same for exactly inspecting particles such as metal and ceramic components that largely influence the inside quality of flat glass.
2. Description of the Related Art
During a flat glass fabrication process, inside particles which are generated when a glass material is melted and made into a flat plate include bubbles, metal, ceramic components and others. Since these inside particles have a large impact on the quality of flat glass, an exact inspection technology is essential. In addition, according to the components of the inside particles, degrees of the quality of flat glass being affected are different. Therefore, it is necessary to distinguish and inspect the components of the inside particles. Particularly, among these inside particles, bubble components do not have a large effect, whereas metal or ceramic components do. Accordingly, even though certain glass contains these bubble components, it is known that the glass can be used as solar cell protecting glass.
As for an inspection device for detecting defects among a transparent plate-shaped body, BF (Bright Field) optical systems and DF (Dark Field) optical systems are widely employed.
A bright field optical system will be described briefly as follows. FIG. 1 shows a bright field optical system for detecting defects which exist among a transparent plate-shaped body. Referring to FIG. 1, a bright field optical system includes a sensor camera 3 which is positioned in the regular reflection direction of a light source 2 with respect to a transparent plate-shaped body 1. Therefore, a light beam radiated from the light source 2 mostly reaches at the sensor camera 3 via two ray paths 2a and 2b, wherein one ray path 2a of the ray paths 2a and 2b corresponds to a light beam reflected against a top surface of the plate-shaped body 1 and the other ray path 2b corresponds to a light beam reflected against a bottom surface of the transparent plate-shaped body. The sensor camera 3 becomes a bright field onto which an image reflected by the ray paths 2a and 2b as above.
In such a bright field optical system, inspections are carried out by photographing reflected images for a transferred transparent plate-shaped body. In the photographing process, the bright field optical system obtains a real image and a virtual image (a shadow) by a reflection light source and it is possible to detect whether the flat glass has a defects or not.
Next, a dark field optical system will be described briefly as follows. FIG. 2 shows a dark field optical system for detecting defects which exist among a transparent plate-shaped body. Referring to FIG. 1, in a dark field optical system, a sensor camera 5 is disposed on a top surface of a transparent plate-shaped body 1, and a light source 6 is disposed on a bottom surface of the transparent plate-shaped body 1, thereby photographing images by using transmitted light instead of reflected light. In other words, the dark field optical system detects defects 4 such as impurities which are existing among the transparent plate-shaped body 1 by collecting dark field components in transmitted light beams 7.
However, when the inspections are carried out by the prior bright field optical systems or the dark field optical systems, although it is easy to perceive the exact position of the defects, it is hard to decide whether the discovered defects largely affect the quality of glass that contains metal and ceramic components, or the defects does not give much effect on the quality of glass that contains bubble components.